The vast majority of who? If you mean a vast majority of your customers calling into a support center, I'd argue that is a very small amount. I'd venture to say very few of peers in my circles call into support outside of account level tasks.
We tech-savvy people have a better understanding of things like compatibility, the drawbacks of third-party/unofficial accessories etc. But try explaining that to someone who has no interest or experience in this, and they'll just not understand - or care.
If Philips had stuck to their decision, it would've meant that, for anyone contact support, they could handle the entirety of the problem. This avoids the boomeranging of "well it might be your bulb, go speak to the people who made it".
I don't know many people who use home automation, lighting systems like this, but of those that do - all but one is not someone I'd consider tech-savvy.
I have no strong feelings one way or the other about this decision. Honestly, if I ever used this, I'd probably stick to first party products. As I get older, I find that I just don't care or want to spend the time fiddling with compatibility issues. If I'm in the market for automated light bulbs, chances are I'll have no problem stretching my budget to first party bulbs.